As his son Otis Redding III strums the tune on his guitar, he mostly has to imagine the recording session back in the summer of 1967 -- he was only 3.

"My mom actually told me that my sister Karla and I, we were in Memphis," he said. "We were actually running 'round in the studio while they were recording."

That summer, Otis Redding spent a week in San Francisco performing at the Fillmore West auditorium. He stayed with legendary concert promoter Bill Graham on his houseboat in Sausalito Bay. Redding died that December in a plane crash in Madison, Wisconsin. The song was released within a month.

"He was already at the peak of his career," said Redding III, "where he was crossing over into a really big market, especially in Europe. After this ("The Dock Of The Bay") came out, it just took his career to a whole other level. Unfortunately he wasn't around to see it."

The song was Redding's only hit to reach number one on the Billboard Pop singles charts. In 1968, it won a Grammy for best R&B song and best R&B vocal performance. Decades later, the song has hit another landmark.

"We're now more than 10 million radio performances. That's amazing to me," said Redding III.